Relationship between Pulmonary Function and the Degree of ...irep.iium.edu.my/32603/1/Kelantan_Research_Day_2013...KELANTAN RESEARCH DAY 30TH OCTOBER 2013 Relationship between Pulmonary

KELANTAN RESEARCH DAY 30TH OCTOBER 2013

Relationship between Pulmonary Function and the Degree of Spinal Deformity among

Adolescent Idiopathic Scoliosis (AIS) Patients.

Joehaimey Johari 1, Sobri Nor1, Andrew Lam2, Ahmad Sabri Omar1, Ahmad Tajudin Abdullah2,

Azriani Ab Rahman3, Mohd Ariff Sharifudin4, Mohd Imran Yusof 5.

1Department of Orthopaedics, Hospital Raja Perempuan Zainab II (HRPZII), Malaysia. 2Department of Orthopaedics, Hospital Sultanah Nurzahirah, Malaysia.

3Department of Community Medicine, School of Medical Sciences, Universiti Sains Malaysia (USM). 4Department of Orthopaedics, Traumatology and Rehabilitation, International Islamic University Malaysia (IIUM).

5Department of Orthopaedics, School of Medical Sciences, Universiti Sains Malaysia (USM).

Scoliosis- Definition

• Is a complex, 3-dimensional spinal deformity: – Coronal – Sagittal (Hypokyphosis) – Axial (rotation)

Idiopathic Scoliosis • International Scoliosis Society (3

types)

– Infantile (birth - 3 years)

– Juvenile (4 - 10 years)

– Adolescent (10 - 17 years)

• Scoliosis Research Society (SRS):

– Early Onset - before 5yrs of age.

– Late onset - after 5yrs of age.

• What is crucial about age of onset is whether a substantial thoracic deformity is present before the age of 5 years, in which case there is real risk of cardiopulmonary compromise.

Adolescent idiopathic scoliosis (AIS) often causes deformity of the thorax. With deformed spine and rib cage, the lung parenchyma is compressed which may

lead to decrease in volume and lung compliance.

Methodology

• A retrospective record review was conducted among patients with adolescent idiopathic scoliosis (AIS) aged 13 to 24 years, admitted to our institution (HRPZII) for surgical intervention from 2000 to 2013.

• A total of 38 patients were studied

Methodology

• The curvature of spinal deformity was measured by Cobb method on anterior-posterior radiographs.

• The forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV 1) were used to evaluate their pre operative pulmonary function.

Cobb Angle Measurement

• Curve magnitude measured in degrees of curvature

• Standard full-length AP radiograph needed.

• Cobb angle - Line drawn along upper end plate of upper end vertebra and lower end plate of lower end vertebra. Perpendiculars drawn from these lines. Angle of intersection measured

• John Cobb was a father figure of scoliosis surgery in America.

Results

Variables Mean (SD) [*n (%) ]

Age 16.7 (6.04)

Sex

male 3 (7.9)*

female 35 (92.1)*

Cobb angle 58.1 (19.63)

Pre operative FEV1 80.5(21.68)

Pre operative FVC 75.3 (20.05)

Table 1: Demographic characteristics of the patients with adolescent idiopathic scoliosis

b (95% Confidence Interval B) p value* R2

FEV1 -.326 (-.683, 0.030) 0.072 0.087

FVC -.319 (-.647, 0.009) 0.057 0.097

Table 2: Relationship between Cobb angle with FVC and FEV1

*Simple Linear Regression

No significant Relationship between Cobb angle with FVC and FEV1

Relationship between Cobb angle and preoperative FEV1 and FVC

• An inverse relationship between spinal deformity and pulmonary function has been reported by a few studies. Vitale, Matsumoto et al. 2008 found that the degree of thoracic curves was negatively correlated with FEV1.

• There was also a trend toward significant negative correlations between thoracic curves and FVC. Patients with larger thoracic curves had lower pulmonary function measured by FEV1 and FVC.

•

L1, L2 & L3

n=5

median

(IQR)

T6, T7 & T8

n=8

median

(IQR)

T9-T12

n=25

median

(IQR)

p value**

FVC 92 (30) 68.5 (36) 74 (19) 0.006

FEV1 93 (49) 67 (41) 82 (26) 0.118

Table 4: Median FVC and FEV1 according to different level of apical vertebrae

** Kruskal- Wallis test

The median FVC was significantly higher in those with affected apical

vertebrae located at L1, L2 and L3 level than those with apical vertebra at

T6, T7 and T8 (p=0.008).

The median FVC was also significantly higher in those with affected

apical vertebra located at L1, L2 and L3 than those with affected T9-T12

(p=0.003)

• more proximally located spinal curve resulted in more impairment in the pulmonary

function.

T6, T7 & T8

n=17

median (IQR)*

T9-T12

n=21

median (IQR)*

p value**

FVC 75 (18) 76 (41) 0.953

FEV1 82 (21) 79 (41) 0.436

Table 5: Median FVC and FEV1 according to different level of upper end vertebrae

** Mann-Whitney test

No significant difference in the Median FVC and FEV1 according to different level of upper end vertebrae

L 1,2,3

n=16

median (IQR)*

T 6-12

n=22

median (IQR)*

p value**

FVC 83.5(19) 70.5 (31) 0.014

FEV1 86(20) 78 (32) 0.055

Table 6: Median FVC and FEV1 according to different level of lower end vertebrae

** Mann- Whitney test

The median FVC was significantly higher

among those with affected L1,2,3 than those

with affected T6-12

Figure 4: Relationship between age and pre operative FVC

b (95% Confidence Interval B) p value* R2

FEV1 -1.038 (-2.200, 0.124) 0.078 0.084

FVC -1.092(-2.152,- 0.031) 0.044 0.108

Relationship between age and FVC and FEV1

*Simple Linear regression

• An increase in age by one year would significantly decrease FVC by 1.092 units . Variation of 10.8 % in FVC was explained by age (R2=0.108).

• There was no significant relationship between age and pre operative FEV1.

• The older the patients, the poorer the pulmonary function was.

• This is supported by other study which described that the decline in spirometric values over 20 years of age was of the same magnitude as the predicted decline due to aging. Thus respiratory failure develops in adults with large angle scoliosis and a low vital capacity when normal aging reduces the ventilatory capacity further (Pehrsson, Bake et al. 1991)

Conclusion & Recommendation

• Impairment of lung function was seen in more severe spinal deformity, more proximally located curve and in older patients.

• Pulmonary impairment from spinal deformity remains to be one of the indications for surgical intervention.

• Pulmonary function testing is useful in the pre operative evaluation of patients with adolescent idiopathic scoliosis.

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